Semiconductor memories have been widely used in various electronic apparatuses such as personal computer, display card and printer. Due to enhanced performances of electronic apparatuses and decreased dimensions thereof, capacity of a semiconductor memory has to be expanded accordingly. An approach is to use a plurality of semiconductor memories at the same time, but it occupies a large space, so that area of a circuit board can not be optimally used. Another semiconductor memory capacity expansion approach is to develop semiconductor memories of high capacities. However, consideration development cost and manufacturing cost are needed for the semiconductor memories of high capacities.
To stack two or more semiconductor memory packages to form a memory device having a high capacity can solve the above problem. However, wiring in each chip of a conventional semiconductor memory stack varies, and thus different specification requirements for respective packages are disadvantageous to manufacture management.
Therefore, it is necessary to propose an approach to overcome the prior art disadvantages.